How do you rewrite the exponential expression as a radical expression b^(- 4/7)?

Apr 30, 2016

There are two laws of indices involved. A negative index indicates a fraction (the reciprocal with a positive index) and a fractional index means there is a power and a root.

Explanation:

Let's deal with the negative in the index first. This simply means that the base is in the denominator and the index is positive:

${b}^{- \frac{6}{7}} = \frac{1}{b} ^ \left(\frac{6}{7}\right)$

The numerator of a fractional index is a power,
the denominator of a fractional index is a root.

This gives us $\frac{1}{7 {\sqrt{b}}^{6}}$